Method and apparatus for configuring channel state information- reference signal

ABSTRACT

Disclosed are a method and an apparatus for configuring a channel state information-reference signal (CSI-RS). The method comprises: a base station determines configuration information of a CSI-RS; the base station generates signaling comprising the configuration information of the CSI-RS; and the base station transmits the signaling comprising the configuration information of the CSI-RS. The configuration information comprises: a port quantity, pilot resource pattern information, and a multiplex mode between CSI-RS ports, when the port quantity is greater than 1, the CSI-RS has M candidate pilot resource patterns, where M is an integer greater than 1. The method and apparatus for configuring a CSI-RS disclosed in embodiments of the present invention can support transmission of a CSI-RS of which the port quantity is greater than 8.

TECHNICAL FIELD

The disclosure relates to the field of communications, and particularlyto a method and apparatus for configuring a Channel StateInformation-Reference Signal (CSI-RS).

BACKGROUND

A Long Term Evolution (LTE)/LTE-Advanced (LTE-A) technology is amainstream 4th-Generation (4G) mobile communication technology.LTE/LTE-A has the following two duplex manners: Frequency DivisionDuplex (FDD) and Time Division Duplex (TDD). A frame structure of theFDD manner is referred to as a frame structure type 1, and a framestructure of the TDD manner is referred to as a frame structure type 2.

FIG. 1 is a schematic diagram of a frame structure type 1. As shown inFIG. 1, the description of the frame structure type 1 is provided asfollows. Each radio frame has a length of T_(f)=307200·T_(s)=10 ms(milliseconds), and consists of 20 slots, and each of the slots has alength of T_(slot)=15360·T_(s)=0.5 ms (milliseconds) and the slots arenumbered from 0 to 19, where T_(s) is a time unit, andT_(s)=1/(15000×2048) seconds; a subframe is defined to consist of twocontinuous slots, that is, a subframe i consists of slots 2i and 2i+1.For the FDD manner, within a 10-millisecond time interval, 10 subframesare configured for downlink transmission, and 10 subframes areconfigured for uplink transmission; uplink transmission and downlinktransmission are performed on different frequencies respectively. In ahalf-duplex FDD manner, User Equipment (UE) may not implementtransmission and reception simultaneously, while in a full-duplex FDDmanner, there is no such a limit.

FIG. 2 is a schematic diagram of a frame structure type 2. As shown inFIG. 2, the description of the frame structure type 2 is provided asfollows. Each radio frame has a length of T_(f)=307200·T_(s=10) ms, andconsists of two half-frames, the half-frames have lengths of153600·T_(s)=5 ms, each half-frame consists of 5 subframes, eachsubframe has a length of 30720.7=1 ms, each subframe is defined toconsist of two slots, that is, a subframe i consists of slots 2i and2i+1, and each of the slots has a length of T_(slot)=15360·T_(s)=0.5 ms,where T_(s) is a unit time, and T_(s)=1/(15000×2048) seconds.

Uplink-downlink configuration of a cell changes among frames, anduplink-downlink transmission occurs in subframes of the frames.Uplink-downlink configuration of a present frame is obtained byhigh-layer signaling.

There are totally 7 uplink-downlink configurations shown in Table 1. Foreach subframe in a radio frame, “D” denotes a downlink subframeconfigured for downlink transmission, “U” denotes an uplink subframeconfigured for uplink transmission, and “S” denotes a special subframe.The special subframe has the following three regions: a Downlink PilotTime Slot (DwPTS), a Guard Period (GP) and an Uplink Pilot Time Slot(UpPTS).

TABLE 1 uplink-downlink Downlink-to-uplink Switch- configuration pointperiodicity Subframe number 0 5 ms 1 5 ms 2 5 ms 3 10 ms  4 10 ms  5 10ms  6 5 ms

LTE/LTE-A technology-based downlink transmission uses an OrthogonalFrequency Division Multiplexing (OFDM) modulation technology, and dataare modulated on a subcarrier in frequency domain and then istransformed to time domain and added with a Cyclic Prefix (CP) to form acomplete time-domain transmission OFDM symbol. The CP is used to resistsymbol interference generated by multiple paths in the time domain andinter-subcarrier interference generated in the frequency domain. Thereare CPs with two lengths in an LTE/LTE-A system, one is a Normal CP(NCP), and the other is an Extended CP (ECP). The ECP is applied to ascenario with a greater multipath delay spread. Under an NCP condition,a subcarrier spacing is 15 kHz; and under an ECP condition, there aretwo subcarrier spacings, i.e., 15 kHz and 7.5 kHz.

A signal transmitted in each slot is described with one or more resourcegrids. A resource grid consists of N_(RB) ^(DL)N_(sc) ^(RB) subcarriersand N_(symb) ^(DL) OFDM symbols, where N_(RB) ^(DL) represents thenumber of Physical Resource Blocks (PRBs) or Resource Blocks (RBs),N_(sc) ^(RB) represents the number of subcarriers in the RBs, andN_(symb) ^(DL) represents the number of the OFDM symbols in the slot.Table 2 shows PRB parameters, and the number of OFDM symbols and thenumber of subcarriers on an RB are shown in Table 2. Table 3 shows OFDMsymbol parameters, and lengths of the CPs are shown in Table 3.

TABLE 2 Configuration N_(sc) ^(RB) N_(symb) ^(DL) NCP Δf = 15 kHz 12 7ECP Δf = 15 kHz 6 Δf = 7.5 kHz 24 3

TABLE 3 Configuration CP length N_(CP, l) NCP Δf = 15 kHz 160 for l = 0144 for l = 1, 2, . . . , 6 ECP Δf = 15 kHz 512 for l = 0, 1, . . . , 5Δf = 7.5 kHz 1024 for l = 0, 1, 2

The number N_(RB) ^(DL) of the PRBs is determined by a downlinktransmission bandwidth configured by a cell, and has a minimum value of6 and a maximum value of 110.

The same PRB on two continuous slots on the same subframe is referred toas a PRB pair.

FIG. 3 is a schematic diagram of a downlink resource grid. As shown inFIG. 3, each unit in the resource grid is referred to as a ResourceElement (RE), and is denoted with an index pair (k,l) where k=0, . . . ,N_(RB) ^(DL)N_(sc) ^(RB)−1 represents a serial number of a subcarrier inthe frequency domain, and 1=0, . . . , N_(symb) ^(DL)−1 represents aserial number of an OFDM symbol in the time domain.

An antenna port is defined as a channel through which a symboltransmitted on the antenna port passes, and may be conjectured by achannel through which another symbol transmitted on the same portpasses. An antenna port is also defined with a corresponding serialnumber for distinguishing between antenna ports and indexing of theantenna port.

A downlink physical channel corresponds to a set of REs, and isconfigured to bear information from an upper layer. Downlink physicalchannels include: a Physical Downlink Shared Channel (PDSCH), a PhysicalMulticast Channel (PMCH), a Physical Broadcast Channel (PBCH), aPhysical Control Format Indicator Channel (PCFICH), a Physical DownlinkControl Channel (PDCCH), a Physical Hybrid Automatic Repeat reQuestIndicator Channel (PHICH) and an Enhanced PDCCH (EPDCCH).

A downlink physical signal corresponds to a set of REs, and is used by aphysical layer and not configured to bear upper-layer information.Downlink physical signals include: a Reference Signal (RS), asynchronization signal and a discovery signal.

RSs are also referred to as pilots, and include the following types:Cell-specific Reference Signals (CRSs), a Multimedia Broadcast SingleFrequency Network (MBSFN) RSs, UE-specific RSs (Demodulation ReferenceSignals (DMRSs)), positioning RSs and CSI-RSs, where the UE-specific RSsfurther include the following two types: UE-specific RSs associated withPDSCH and DMRSs associated with EPDCCH.

A CSI-RS is used for UE to predict a channel state. A CSI-RS transmittedby with Non-Zero Power is referred to as an NZP CSI-RS. Sometimes foravoiding interference, data transmission on some REs on a PDSCH is to beavoided, Zero Power (ZP) transmission of a CSI-RS is used instead, andat this time, the CSI-RS is referred to as a ZP CSI-RS, and acorresponding RE set is referred to as a ZP CSI-RS resource. Sometimesfor measuring the interference. ZP transmission of a CSI-RS is used, andat this time, a corresponding RE set is referred to as aCSI-Interference Measurement (CSI-IM) resource.

A CSI-RS configuration is used to indicate an RE mapped by a CSI-RS.i.e., an RE for transmitting the CSI-RS, and a CSI-RS configurationserial number is used to distinguish different CSI-RS configurations. AnRE set for transmitting or mapping a CSI-RS under a CSI-RS configurationis referred to as a CSI-RS resource pattern. A CSI-RS subframeconfiguration is used to indicate a subframe where a CSI-RS istransmitted.

A CSI-RS configuration is a CSI-RS configuration under a certain numberof antenna ports, for example, a CSI-RS configuration corresponding to 8antenna ports and with a configuration serial number 0 (an 8-port CSI-RSconfig #0). A CSI-RS resource pattern is a CSI-RS resource pattern undera certain number of antenna ports, for example, a CSI-RS resourcepattern corresponding to 8 antenna ports and with an index number of 0(an 8-port CSI-RS resource pattern #0). A configuration serial number isusually an index number.

An RE set for transmitting or mapping CSI-RSs with part of the portsunder a CSI-RS configuration is referred to as an RS resource patternwith part of ports, for example, an RS resource pattern with port serialnumbers of {15, 16, 17, 18}.

A related technology supports CSI-RSs with 1, 2, 4 or 8 ports, andCSI-RS resource patterns with these numbers of ports are repeated oneach PRB pair within a bandwidth range in a transmission subframe.

All RE sets configured as CSI-RS resource patterns with differentnumbers of ports are the same, that is, all RE sets configured as 2-portCSI-RS resource patterns are equal to all RE sets configured as 4-portCSI-RS resource patterns and equal to all RE sets configured as 8-portCSI-RS resource patterns. For example, for a common CSI-RS configurationcondition of a frame structure type 1 and a frame structure type 2, allRE sets configured as CSI-RS resource patterns with different numbers ofports are the same, and the number of REs on a PRB is 40.

FIG. 4 is a resource pattern of a 4-port CSI-RS on an RB pair. FIG. 5 isa resource pattern of an 8-port CSI-RS on an RB pair.

For fully utilizing power and improving channel measurement accuracy,CSI-RSs of various ports are further divided into groups, that is, agroup includes CSI-RSs of multiple ports, and there are one or moregroups. CSI-RSs of the ports in a group are mapped onto the same set ofREs in a code division multiplexing scheme. For example, the number ofports in a group is N, and a CSI-RS sequence is {r₀, r₁, . . . ,r_(N−1)}; in addition, there is a sequence set {w₀ ^(p), w₁ ^(p), . . ., w_(N−1) ^(p)} with a length of N, where p=K+0, K+1, . . . , K+N−1,there are N sequences in the group, and the sequences in the group aremutually orthogonal, that is, Σ_(m=0) ^(N−1)w_(m) ^(i)w_(m) ^(j)=0,where i,j=K+0, K+1, . . . , K+N−1, and i≠j; the sequence {w₀ ^(p), w₁^(p), . . . , w_(N−1) ^(p)} is modulated by the CSI-RS sequence {r₀, r₁,. . . , r_(N−1)} to obtain a CSI-RS sequence {r₀w₀ ^(p), r₁w₁ ^(p), . .. , r_(N−1)w_(N−1) ^(p)} corresponding to a port p; and corresponding tothe same set of REs, elements in the CSI-RS sequence corresponding tothe port p are mapped to the REs in a one-to-one corresponding manner. Nis a multiplexing length.

In the related technology, a manner of multiplexing and mapping CSI-RSsbetween ports to REs is as follows: the ports are divided into groups,for example, totally 4 groups {15, 16}, {17, 18}, {19, 20} and {21, 22},and the four groups are multiplexed to the REs in a frequency divisionmanner; and within each group, the CSI-RSs of the ports are multiplexedto the REs in the time domain in a code division manner, for example,the CSI-RS of the port 15 and the CSI-RS of the port 16 are multiplexedin the time domain in the code division manner.

A base station notifies UE of information about a CSI-RS throughupper-layer signaling, and the information includes: a CSI-RS resourceconfiguration identity, a number of ports for the CSI-RS, CSI-RSconfiguration and CSI-RS subframe configuration.

A CRS may be configured to not only measure a channel state but alsoreceive estimation about a channel coefficient during demodulation.However, along with increase of the number of ports, an overhead issharply increased. Therefore, CRS is no longer used to measure channelstates when the number of ports is 8, and instead, CSI-RSs which are lowin RS density and low in overhead are used. However, along withdevelopment of the technology and requirement, technologies appliedunder a larger number of antenna ports for example, 12 or 16 ports, areto be developed, and measurement over channel states under the largernumber of ports is involved. However, the related technology may notsupport 12 or 16-port CSI-RS transmission. In addition, when the numberof the ports is increased to 12 or 16, there may be brought the problemsof high overhead, reduction in channel measurement performance, high UEcomplexity and the like.

SUMMARY

In order to solve the technical problem, embodiments of the disclosureprovide a method and apparatus for configuring a CSI-RS, which maysupport CSI-RS transmission with more than 8 ports.

In order to achieve the technical purpose, the embodiments of thedisclosure provide a method for configuring a CSI-RS, which may includethat: a base station determines configuration information of a CSI-RS;the base station generates signaling including the configurationinformation of the CSI-RS; and the base station transmits the signalingincluding the configuration information of the CSI-RS, wherein theconfiguration information may include: a number of ports, RS resourcepattern information and an inter-CSI-RS-port multiplexing scheme, andwhen the number of the ports is larger than 1, there may be M candidateRS resource patterns for the CSI-RS, where M is an integer greater than1.

The embodiments of the disclosure further provide a CSI-RS configurationdevice, which may include: a determination module, configured todetermine configuration information of a CSI-RS; a generation module,configured to generate signaling including the configuration informationof the CSI-RS; and a transmission module, configured to transmit thesignaling including the configuration information of the CSI-RS, whereinthe configuration information may include: a number of ports, RSresource pattern information and an inter-CSI-RS-port multiplexingscheme, and when the number of the ports is larger than 1, there may beM candidate RS resource patterns for the CSI-RS, where M is an integergreater than 1.

In the embodiments of the disclosure, a computer storage medium isfurther provided, the computer storage medium may store an executableinstruction, and the executable instruction may be configured to executethe method for configuring the CSI-RS in the embodiments.

In the embodiments of the disclosure, the base station determines theconfiguration information of the CSI-RS; the base station generates thesignaling including the configuration information of the CSI-RS; and thebase station transmits the signaling including the configurationinformation of the CSI-RS, wherein the configuration informationincludes: the number of the ports, the RS resource pattern informationand the inter-CSI-RS-port multiplexing scheme, and when the number ofthe ports is larger than 1, there are the M candidate RS resourcepatterns for the CSI-RS, where M is an integer greater than 1. By theembodiments of the disclosure, CSI-RS transmission with more than 8 (forexample, 12 or 16) ports is supported.

By the embodiments of the disclosure, under the condition of providing alarger RS multiplexing factor, an overhead is reduced, channelestimation quality is improved, transmission and receiving complexity islowered, and meanwhile, CSI-RS transmission with 12 or 16 ports issupported.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a frame structure type 1.

FIG. 2 is a schematic diagram of a frame structure type 2.

FIG. 3 is a schematic diagram of a downlink resource grid.

FIG. 4 is a resource pattern of a 4-port CSI-RS on an RB pair.

FIG. 5 is a resource pattern of an 8-port CSI-RS 8 on an RB pair.

FIG. 6 is a flowchart of a method for configuring a CSI-RS according toan embodiment of the disclosure.

FIG. 7 is a schematic diagram of a device for configuring a CSI-RSaccording to an embodiment of the disclosure.

FIG. 8 is a schematic diagram of code division multiplexing of eachgroup of CSI-RSs to four REs of continuous subcarriers in the case of 16ports.

FIG. 9 is a schematic diagram of code division multiplexing of eachgroup of CSI-RSs to four REs of continuous subcarriers in the case of 12ports.

FIG. 10 is a pattern with a maximum frequency interval that is smallerthan 9 on a PRB pair in the case that an RS density is one RE in eachPRB pair for each port.

FIG. 11 is a pattern with a maximum time-domain interval that is smallerthan 6.

FIG. 12 is a pattern with a maximum time-domain interval that is smallerthan 5.

FIG. 13 is a pattern with an RS density of two REs in every three PRBpairs for each port in the case of 12 ports.

FIG. 14 is a pattern with an RS density of one RE in every two PRB pairsfor each port in the case of 12 ports.

FIG. 15 is a pattern combined by a pattern with 8 ports and two patternswith 2 ports in the case that the number of ports of 12.

FIG. 16 is mapping of each group of code division multiplexed RS symbolsonto REs of a PRB pair in a 4-port resource pattern.

DETAILED DESCRIPTION

The embodiments of the disclosure will be described below in combinationwith the drawings in detail. It is to be understood that the embodimentsdescribed below are used to describe and explain the disclosure and notintended to limit the disclosure.

FIG. 6 is a flowchart of a method for configuring a CSI-RS according toan embodiment of the disclosure. As shown in FIG. 6, the method forconfiguring the CSI-RS provided by the embodiment includes the followingoperations.

In S11, a base station determines configuration information of a CSI-RS.

In S12, the base station generates signaling including the configurationinformation of the CSI-RS.

In S13, the base station transmits the signaling including theconfiguration information of the CSI-RS.

Here, the configuration information includes: a number of ports, RSresource pattern information and an inter-CSI-RS-port multiplexingscheme. When the number of the ports is larger than 1, there are Mcandidate RS resource patterns for the CSI-RS, where M is an integergreater than 1.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is larger than a first threshold value (TH1), atleast two inter-CSI-RS-port multiplexing schemes are used for the Mcandidate RS resource patterns.

Specifically, an RS symbol of a port is transmitted by one port, anddata symbols on a PDSCH are transmitted by multiple ports. If an RSsymbol of one port is transmitted on an RE, all power on the RE may beused for transmission of the port, and is equivalent to a sum of powersfor all ports transmitting data symbols on an RE; and if the power fortransmitting an RS symbol by a port is excessively higher than power fortransmitting data symbols by the same port, transmission accuracy of theRS symbol may be influenced. A code division multiplexing scheme is usedfor RS symbols of multiple ports, so that power may be fully utilized,and RS symbol transmission power of each port may be reduced. In thecase that the number of the ports is smaller, a smaller code divisionmultiplexing length may be used; in the case that the number of theports is increased, a larger code division multiplexing length may beused; and in the case that the number of the ports is larger, the numberof the ports is split into several groups of a smaller number of portssometimes, and a smaller code division multiplexing length is used fortheir RSs. Sometimes for changing a port multiplexing number, a numberof time-domain multiplexing OFDM symbols is increased; or, the number ofthe time-domain multiplexing OFDM symbols is decreased; or, afrequency-domain multiplexing interval is increased; or, thefrequency-domain multiplexing interval is decreased.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a firstmultiplexing scheme is used for CSI-RS ports in the first pattern set, asecond multiplexing scheme is used for CSI-RS ports in the secondpattern set, and the first multiplexing scheme is different from thesecond multiplexing scheme.

Specifically, in the case that a total number of provided ports is keptunchanged, a number of ports in a group is large sometimes, a largernumber of REs are occupied for their multiplexing, a large number of REsare required to be occupied, and then a multiplexing scheme with alarger number of OFDM symbols is required to be used or a multiplexingscheme with a decreased frequency-domain interval is used; and a numberof ports in a group is small sometimes, a smaller number of REs areoccupied for their multiplexing, a smaller number of REs are required tobe occupied, and then a multiplexing scheme with a smaller number ofOFDM symbols is required to be used or a multiplexing scheme with anincreased frequency-domain interval is used.

Specifically, on the other aspect, in the case that the number of theports is large, an RS resource pattern corresponding to a large codedivision multiplexing length may be used; and in the case that thenumber of the ports is large, the RS is split into several RSs withfewer ports sometimes, and an RS resource pattern corresponding to asmaller code division multiplexing length is used for their RSs.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a firstmultiplexing scheme is used for CSI-RS ports in the first pattern set,the first multiplexing scheme or a second multiplexing scheme is usedfor CSI-RS ports in the second pattern set, the first multiplexingscheme is different from the second multiplexing scheme, and themultiplexing scheme used for the CSI-RS ports of the second pattern setis configured via signaling of the base station.

Specifically, in the case that a total number of provided ports is keptunchanged, a number of ports in a group is large sometimes, a largernumber of REs are occupied for multiplexing of the ports, a largernumber of REs are required to be occupied, and then a multiplexingscheme with a larger number of OFDM symbols is required to be used or amultiplexing scheme with a decreased frequency-domain interval is used;and a number of ports in a group is small sometimes, a smaller number ofREs are occupied for multiplexing of the ports, a smaller number of REsare required to be occupied, and then a multiplexing scheme with asmaller number of OFDM symbols is required to be used or a multiplexingscheme with an increased frequency-domain interval is used. For makingpart of patterns applicable to the condition that the number of theports in the group is large and also applicable to the condition thatthe number of the ports in the group is small, the first multiplexingscheme is used for the CSI-RS ports of the first pattern set, and thefirst multiplexing scheme or the second multiplexing scheme is used forthe CSI-RS ports of the second pattern set.

Specifically, on the other aspect, in the case that the number of theports is large, an RS resource pattern corresponding to a larger codedivision multiplexing length may be used; and in the case that thenumber of the ports is large, the RS is split into several RSs withfewer ports sometimes, and an RS resource pattern corresponding to asmaller code division multiplexing length is used. For making part ofpatterns applicable to the condition that the number of the ports islarge and also applicable to the condition of splitting into RSs withthe fewer ports, the first multiplexing scheme is used for the CSI-RSports of the first pattern set, and the first multiplexing scheme or thesecond multiplexing scheme is used for the CSI-RS ports of the secondpattern set.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into three sets, a firstmultiplexing scheme is used for CSI-RS ports of the first pattern set, asecond multiplexing scheme is used for CSI-RS ports of the secondpattern set, the first multiplexing scheme or the second multiplexingscheme is used for CSI-RS ports of the third pattern set, the firstmultiplexing scheme is different from the second multiplexing scheme,and the multiplexing scheme used for the CSI-RS ports of the thirdpattern set is configured via signaling of the base station.

Specifically, in the case that a total number of provided ports is keptunchanged, the number of ports in a group is large sometimes, a largernumber of REs are occupied for multiplexing of the ports, a largernumber of REs are required to be occupied, and then a multiplexingscheme with a larger number of OFDM symbols is required to be used or amultiplexing scheme with a decreased frequency-domain interval is used;and the number of ports in a group is small sometimes, a smaller numberof REs are occupied for multiplexing of the ports, a smaller number ofREs are required to be occupied, and then a multiplexing scheme with asmaller number of OFDM symbols is required to be used or a multiplexingscheme with an increased frequency-domain interval is used. For makingpart of patterns applicable to the condition that the number of theports in the group is larger and also applicable to the condition thatthe number of the ports in the group is smaller, the first multiplexingscheme is used for the CSI-RS ports of the first pattern set, the firstmultiplexing scheme or the second multiplexing scheme is used for theCSI-RS ports of the second pattern set, and the first multiplexingscheme or the second multiplexing scheme is used for the CSI-RS ports ofthe third pattern set.

Specifically, in the case that the number of the ports is small, asmaller code division multiplexing length may be used; in the case thatthe number of the ports is increased, a larger code divisionmultiplexing length may be used; and the in the case that the number ofthe port is larger, the RS is split into several RSs with fewer ports,and a smaller code division multiplexing length is used. Part ofpatterns are applied to the condition of splitting into several RSs withfewer ports, part of patterns are applied to the condition that thenumber of the ports is large, and part of patterns are not only appliedto the condition of splitting into several RSs with fewer ports but alsoapplied to the condition that the number of the ports is large.

Preferably, the multiplexing scheme is a code division multiplexingscheme.

Preferably, the first code division multiplexing scheme is code divisionmultiplexing with an orthogonal code length of 2, and the second codedivision multiplexing scheme is code division multiplexing with anorthogonal code length of 4.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is larger than a second threshold value, at leasttwo types of RS densities are used for the M candidate RS resourcepatterns.

Specifically, there are certain limits made to REs which may beconfigured to transmit CSI-RSs in a PRB pair. For example, under an NCPcondition, the number of REs configured for CSI-RS transmission of aframe structure type 1 and a frame structure type 2 is 40. In the casethat the number of the ports is increased and an RS density of each portis kept unchanged, available RS resource patterns are reduced. Forexample, there are 5 RS resource patterns for 8-port CSI-RSs under adensity of one RE in each PRB pair for each port, while there may bemerely two RS resource patterns for 16-port CSI-RSs under a density ofone RE in each PRB pair for each port. For providing more RS patterns inthe case that the number of the ports is larger, a manner of reducingthe RS density of the ports may be used. However, under the condition oflow channel relevance and frequency-domain relevance, reducing the RSdensity may influence channel estimation performance, and it may benecessary to reserve resource patterns under higher RS density.Therefore, in the case that the number of the ports is larger, usingmultiple types of RS densities may not only provide more RS patterns butalso ensure channel estimation performance under a complex condition.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a first typeof RS density is used for the first pattern set, a second type of RSdensity is used for the second pattern set, and the first type of RSdensity is different from the second type of RS density.

Here, the two pattern sets correspond to two types of RS densitiesrespectively, and may be selected for use according to a practicalcondition.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, the inter-CSI-RS-port multiplexing scheme uses acode division multiplexing length of 4, and four REs for mapping of eachgroup of code division multiplexed RS symbols are located on twocontinuous subcarriers.

Specifically, an RS on each port is transmitted by the single port, andfor fully utilizing power, power higher than data transmission power ona single port is used to transmit the RS. Since power may still not befully utilized to transmit an RS under a limit of a peak-to-averageratio of a power device, a code division multiplexing scheme is used. Ifchannel coefficients between REs for code division multiplexing aregreatly different, greater interference may be introduced. There aresubstantially no difference between channel coefficients of adjacentsubcarriers, so that REs for code division multiplexing mapping oncontinuous subcarriers may be selected to solve the problem.

Preferably, the M candidate RS resource patterns include that: a maximumfrequency interval of REs on a PRB pair in a pattern of which an RSdensity is one RE in each PRB pair for each port is less than or equalto the number, which is a third threshold value (TH3), of subcarriers,and the maximum frequency interval is a difference between a highestfrequency and a lowest frequency of frequency bands in which the REs arelocated.

Alternatively, the third threshold value is 9.

Specifically, channel estimation with a CSI-RS requires comparisonbetween channel coefficients of each port, and an excessive frequencyinterval of REs of the same pattern on the same PRB pair may introduce aphase comparison error between different ports due to a frequency changeof a channel. The third threshold value TH3 is 9, so that the REs may beprevented from being simultaneously distributed in the vicinity of alowest frequency and in the vicinity of a highest frequency of the sameRB.

Preferably, the M candidate RS resource patterns include that: a maximumtime-domain interval of REs on each RS resource pattern is smaller thana fourth threshold value (TH4), where the maximum time-domain intervalis a difference value between a last one and a first one of OFDM symbolsin which the REs are located.

Alternatively, the fourth threshold value is 6.

Alternatively, the fourth threshold value is 5.

Specifically, channel estimation with a CSI-RS requires comparisonbetween channel coefficients of each port, and an excessive timeinterval of REs of the same pattern may introduce a phase comparisonerror between different ports due to a time change of a channel. Thefourth threshold value is 5, so that CSI-RSs of the same pattern may becontrolled to use five OFDM symbols at a smallest interval in OFDMsymbols for conventional CSI-RS mapping. The fourth threshold value is6, so that the CSI-RSs of the same pattern may be controlled to use OFDMsymbols at largest intervals in the OFDM symbols for conventional CSI-RSmapping.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to an RS resource pattern under a number ofports of 8, moreover, an RS density is two REs in every three PRB pairsfor each port, and different RS resource patterns correspond todifferent 8-port RS resource patterns.

Specifically, when the number of the ports is 12, an RS resource patternuses an 8-port RS resource pattern, meanwhile, the RS density isdecreased, and a larger number of RS resource patterns may be providedcompared with adoption of the RS density of one RE in each PRB pair foreach port. In addition, for avoiding waste of REs, the RS density of twoREs in every three PRB pairs for each port is used.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to an RS resource pattern under a number ofports of 4 and an RS resource pattern under a number of ports of 2 andis on the same two OFDM symbols, an RS density is one RE in every twoPRB pairs for each port, and different RS resource patterns correspondto combinations of different RS resource patterns under the number ofthe ports of 4 and RS resource patterns under the number of the ports of2.

Specifically, when the number of the ports is 12, an RS resource patternuses a combination of a 4-port RS resource pattern and a 2-port RSresource pattern, meanwhile, the RS density is decreased, and a largernumber of RS resource patterns may be provided compared with adoption ofthe RS density of one RE in each PRB pair for each port. Using the sametwo OFDM symbols rather than more OFDM symbols may avoid introduction ofa channel estimation error due to an excessive distribution of the RSpatterns on the time domain.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to an 8-port RS resource pattern and two2-port RS resource patterns, moreover, the two RS resource patternsunder the two port numbers are located on the same two OFDM symbols andadjacent in frequency domain, an RS density is one RE in each PRB pairfor each port, and different RS resource patterns correspond tocombinations of different 8-port RS resource patterns and 2-port RSresource patterns.

Specifically, when the number of the ports is 12, an RS resource patternuses a combination of an 8-port RS resource pattern and two 2-port RSresource patterns, where the two 2-port RS resource patterns mayflexibly form multiple combinations to implement multiple portmultiplexing schemes.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to two groups of ports, a first codedivision multiplexing scheme is used for the first group of ports, asecond code division multiplexing scheme is used for the second group ofports, and the first code division multiplexing scheme is different fromthe second code division multiplexing scheme.

Here, different multiplexing schemes are used for the two groups ofports respectively, and the same pattern meets two differentmultiplexing schemes.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, each RS resource pattern corresponds to two groupsof ports, a first code division multiplexing scheme is used for thefirst group of ports, the first code division multiplexing scheme or asecond code division multiplexing scheme is used for the second group ofports, the first code division multiplexing scheme is different from thesecond code division multiplexing scheme, and the code divisionmultiplexing scheme used for the second group of ports is configured viasignaling of the base station.

Specifically, there may be two corresponding code division multiplexingschemes in the same RS pattern, the first code division multiplexingscheme is used for the first group of ports, and the first code divisionmultiplexing scheme or the second code division multiplexing scheme maybe used for the second group of ports, so that compatibility of thesecond group of ports is improved.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, each RS resource pattern corresponds to two groupsof ports, a first code division multiplexing scheme or a second codedivision multiplexing scheme is used for the first group of ports, thefirst code division multiplexing scheme or the second code divisionmultiplexing scheme is used for the second group of ports, the firstcode division multiplexing scheme is different from the second codedivision multiplexing scheme, the code division multiplexing scheme usedfor the first group of ports is configured via signaling of the basestation, and the code division multiplexing scheme used for the secondgroup of ports is configured by the signaling of the base station.

Specifically, there may be two corresponding code division multiplexingschemes in the same RS pattern, the first code division multiplexingscheme or the second code division multiplexing scheme is used for thefirst group of ports, and the first code division multiplexing scheme orthe second code division multiplexing scheme may be used for the secondgroup of ports, so that compatibility of the first group of ports andthe second group of ports is improved.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, the inter-CSI-RS-port multiplexing scheme uses acode division multiplexing length of 4, and code division multiplexed RSsymbols of each group are mapped to REs on a PRB pair in a 4-portresource pattern.

Specifically, a manner of mapping code division multiplexed RS symbolsin a same group to REs is added to map 4 ports in a same group to a4-port resource pattern to achieve compatibility with a conventional4-port RS resource pattern.

Preferably, the operation that the base station determines theconfiguration information of the CSI-RS includes that: when the codedivision multiplexing length is 4, a first mapping manner or a secondmapping manner is used to map at least one group of code divisionmultiplexed RS symbols to REs. The first mapping manner is mapping thecode division multiplexed RS symbols onto continuous subcarriers, thesecond mapping manner is mapping the code division multiplexed RSsymbols onto discontinuous subcarriers and the manner of mapping thegroup of the code division multiplexed RS symbols to the REs isconfigured via signaling of the base station.

Specifically, the first mapping manner may achieve a channel estimationperformance gain for code division multiplexing, and the second mappingmanner does not require continuity of the subcarriers, has highermapping flexibility, and may be compatible with a conventional 4-port RSpattern. The manner of mapping the code division multiplexed RS symbolsin a same group to the REs is notified via the signaling to meet arequirement of a practical scenario.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, in a firstpattern set, a first mapping manner is used to map code divisionmultiplexed RS symbols in a same group to REs, and in a second patternset, a second mapping manner is used to map code division multiplexed RSsymbols in a same group to REs, and the first mapping manner isdifferent from the second mapping manner.

The two sets correspond to different manners of mapping the RS symbolsto the REs respectively to meet different requirements.

Preferably, the operation that the base station determines theconfiguration information of the CSI-RS includes that: when theinter-CSI-RS-port multiplexing scheme uses the code divisionmultiplexing length of 4 and the ports are grouped for code divisionmultiplexing, a port grouping manner is configured via signaling of thebase station, the port grouping manner including two port groupingmanners.

Specifically, there are two port grouping manners for the ports to meetdifferent grouping requirements, and notification with the signaling mayfacilitate use of different port grouping manners according to therequirement of the practical scenario.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a first portgrouping manner is used for CSI-RS ports in the first pattern set, asecond port grouping manner is used for CSI-RS ports in the secondpattern set, and the first port grouping manner is different from thesecond port grouping manner.

The two sets correspond to different port grouping manners respectivelyto meet different requirements.

FIG. 7 is a schematic diagram of a device for configuring a CSI-RSaccording to an embodiment of the disclosure. As shown in FIG. 7, thedevice for configuring the CSI-RS provided by the embodiment is arrangedat a base station, and includes: a determination module 1101, ageneration module 1102 and a transmission module 1103, wherein thedetermination module 1101 is arranged to determine configurationinformation of a CSI-RS; the generation module 1102 is configured togenerate signaling including the configuration information of theCSI-RS; and the transmission module 1103 is configured to transmit thesignaling including the configuration information of the CSI-RS, whereinthe configuration information includes: a number of ports, RS resourcepattern information and an inter-CSI-RS-port multiplexing scheme; andwhen the number of the ports is larger than 1, there exist M candidateRS resource patterns for the CSI-RS, where M is an integer greater than1.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is larger than a first threshold value, at least twointer-CSI-RS-port multiplexing schemes are used for the M candidate RSresource patterns.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a firstmultiplexing scheme is used for CSI-RS ports of the first pattern set, asecond multiplexing scheme is used for CSI-RS ports of the secondpattern set, and the first multiplexing scheme is different from thesecond multiplexing scheme.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a firstmultiplexing scheme is used for CSI-RS ports of the first pattern set,the first multiplexing scheme or a second multiplexing scheme is usedfor CSI-RS ports of the second pattern set, the first multiplexingscheme is different from the second multiplexing scheme, and themultiplexing scheme used for the CSI-RS ports of the second pattern setis configured via signaling of a base station.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into three sets, a firstmultiplexing scheme is used for CSI-RS ports of the first pattern set, asecond multiplexing scheme is used for CSI-RS ports of the secondpattern set, the first multiplexing scheme or the second multiplexingscheme is used for CSI-RS ports of the third pattern set, the firstmultiplexing scheme is different from the second multiplexing scheme,and the multiplexing scheme used for the CSI-RS ports of the thirdpattern set is configured via signaling of the base station.

Preferably, the multiplexing scheme is a code division multiplexingscheme.

Preferably, the first code division multiplexing scheme is code divisionmultiplexing with an orthogonal code length of 2, and the second codedivision multiplexing scheme is code division multiplexing with anorthogonal code length of 4.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is larger than a second threshold value, at leasttwo types of RS densities are used for the M candidate RS resourcepatterns.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a first typeof RS density is used for the first pattern set, a second type of RSdensity is used for the second pattern set, and the first type of RSdensity is different from the second type of RS density.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, the inter-CSI-RS-port multiplexing scheme uses acode division multiplexing length of 4, and four REs for mapping of codedivision multiplexed RS symbols of each group are located on twocontinuous subcarriers.

Preferably, the M candidate RS resource patterns include that: a maximumfrequency interval of REs on a PRB pair in a pattern of which an RSdensity is one RE in each PRB pair for each port is less than or equalto the number, which is a third threshold value, of subcarriers, and themaximum frequency interval is a difference between a highest frequencyand a lowest frequency of frequency bands in which the REs are located.

Alternatively, the third threshold value is 9.

Preferably, the M candidate RS resource patterns include that: a maximumtime-domain interval of REs on each RS resource pattern is smaller thana fourth threshold value, wherein the maximum time-domain interval is adifference value between a last one and a first one of OFDM symbols inwhich the REs are located.

Alternatively, the fourth threshold value is 6.

Alternatively, the fourth threshold value is 5.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to an RS resource pattern under a number ofports of 8, moreover, an RS density is two REs in every three PRB pairsfor each port, and different RS resource patterns correspond todifferent RS resource patterns under the number of the ports of 8.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to an RS resource pattern under a number ofports of 4 and an RS resource pattern under a number of ports of 2 andis on the same two OFDM symbols, an RS density is one RE in every twoPRB pairs for each port, and different RS resource patterns correspondto combinations of different RS resource patterns under the number ofthe ports of 4 and RS resource patterns under the number of the ports of2.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to an RS resource pattern under a number ofports of 8 and two RS resource patterns under a number of ports of 2,moreover, the two RS resource patterns under the two port numbers arelocated on the same two OFDM symbols and adjacent on a frequency domain,an RS density is one RE in each PRB pair for each port, and different RSresource patterns correspond to combinations of different RS resourcepatterns under the number of the ports of 8 and RS resource patternsunder the number of the ports of 2.

Preferably, the M candidate RS resource patterns include that: when thenumber of the ports is 12, in an RS resource pattern set, each RSresource pattern corresponds to two groups of ports, a first codedivision multiplexing scheme is used for the first group of ports, asecond code division multiplexing scheme is used for the second group ofports, and the first code division multiplexing scheme is different fromthe second code division multiplexing scheme.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, each RS resource pattern corresponds to two groupsof ports, a first code division multiplexing scheme is used for thefirst group of ports, the first code division multiplexing scheme or asecond code division multiplexing scheme is used for the second group ofports, the first code division multiplexing scheme is different from thesecond code division multiplexing scheme, and the code divisionmultiplexing scheme used for the second group of ports is configured viasignaling of the base station.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, each RS resource pattern corresponds to two groupsof ports, a first code division multiplexing scheme or a second codedivision multiplexing scheme is used for the first group of ports, thefirst code division multiplexing scheme or the second code divisionmultiplexing scheme is used for the second group of ports, the firstcode division multiplexing scheme is different from the second codedivision multiplexing scheme, the code division multiplexing scheme usedfor the first group of ports is configured via signaling of the basestation, and the code division multiplexing scheme used for the secondgroup of ports is configured by the signaling of the base station.

Preferably, the M candidate RS resource patterns include that: in an RSresource pattern set, the inter-CSI-RS-port multiplexing scheme uses acode division multiplexing length of 4, and code division multiplexed RSsymbols of each group are mapped to REs on a PRB pair in a resourcepattern under the number of the ports of 4.

Preferably, that the determination module is configured to determine theconfiguration information of the CSI-RS includes that: when the codedivision multiplexing length is 4, a first mapping manner or a secondmapping manner is used to map at least one group of code divisionmultiplexed RS symbols to REs, the first mapping manner being mappingthe code division multiplexed RS symbols onto continuous subcarriers,the second mapping manner being mapping the code division multiplexed RSsymbols onto discontinuous subcarriers and the manner for mapping thecode division multiplexed RS symbols of the group to the REs beingconfigured via signaling of the base station.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, in a firstpattern set, a first mapping manner is used to map code divisionmultiplexed RS symbols in a same group to REs, and in a second patternset, a second mapping manner is used to map code division multiplexed RSsymbols in a same group to REs, and the first mapping manner isdifferent from the second mapping manner.

Preferably, that the determination module is configured to determine theconfiguration information of the CSI-RS includes that: when theinter-CSI-RS-port multiplexing scheme uses the code divisionmultiplexing length of 4 and the ports are grouped for code divisionmultiplexing, a port grouping manner is configured via signaling of thebase station, the port grouping manner including two types.

Preferably, the M candidate RS resource patterns include that: the Mcandidate RS resource patterns are divided into two sets, a first portgrouping manner is used for CSI-RS ports of the first pattern set, asecond port grouping manner is used for CSI-RS ports of the secondpattern set, and the first port grouping manner is different from thesecond port grouping manner.

During a practical application, the transmission module is acommunication component with an information transmission capability, forexample, a transmitter, and the determination module and the generationmodule are components with an information processing capability, forexample, a processor. However, there are no limits made in thedisclosure. The modules may be, for example, combinations of softwareand/or hardware capable of realizing certain functions.

The disclosure will be described below with multiple specificembodiments.

Embodiment 1

In the embodiment, a base station determines configuration informationof a CSI-RS at first, then generates signaling including theconfiguration information of the CSI-RS and finally transmits thesignaling including the configuration information of the CSI-RS. Forexample, a bits are used to represent port number information, b bitsare used to represent RS resource pattern information, and c bits areused to represent an inter-CSI-RS-port multiplexing scheme, wherea+b+c=X.

Or, a bits may be used to represent the port number information, and bbits are used to represent a joint code of the RS resource patterninformation and the inter-CSI-RS-port multiplexing scheme, where a+b=X.

Or, X bits may be used to represent joint coding of the port numberinformation, the RS resource pattern information and theinter-CSI-RS-port multiplexing scheme.

Or, a bits may be used to represent the port number information, b bitsare used to represent the RS resource pattern information, andmeanwhile, the RS resource pattern information prompts theinter-CSI-RS-port multiplexing scheme.

Herein, the number of ports may be selected from {1, 2, 4, 8, 12, 16}.

When the number of the ports is larger than 1, there may be M candidateRS resource patterns for the CSI-RS, where M is an integer greater than1.

Embodiment 2

In the embodiment, when the number of the ports is larger than a firstthreshold value (TH1), the M candidate RS resource patterns adopt atleast two inter-CSI-RS-port code division multiplexing schemes, where Mis an integer greater than 1. TH1 may be selected from {4, 8, 12}. Theinter-CSI-RS-port code division multiplexing schemes include codedivision multiplexing with a length of 2, code division multiplexingwith a length of 4, code division multiplexing in time domain, codedivision multiplexing in frequency domain, code division multiplexing inboth the time domain and the frequency domain and a combination of themanners.

Embodiment 3

In the embodiment, the M candidate RS resource patterns are divided intotwo sets, a first multiplexing scheme is used for CSI-RS ports of thefirst pattern set, a second multiplexing scheme is used for CSI-RS portsof the second pattern ports, and the first multiplexing scheme isdifferent from the second multiplexing scheme, wherein M is an integergreater than 1.

For example, the first code division multiplexing scheme used for theCSI-RS ports of the first pattern sets uses a code division multiplexinglength of 2, and the second code division multiplexing scheme used forthe CSI-RS ports of the second pattern set uses a code divisionmultiplexing length of 4; or the first code division multiplexing schemeused for the CSI-RS ports of the first pattern set uses the codedivision multiplexing length of 4, and the second code divisionmultiplexing scheme used for the CSI-RS ports of the second pattern setuses the code division multiplexing length of 2.

Embodiment 4

In the embodiment, the M candidate RS resource patterns are divided intotwo sets, a first multiplexing scheme is used for CSI-RS ports of thefirst pattern set, the first multiplexing scheme or a secondmultiplexing scheme is used for CSI-RS ports of the second pattern set,and the first multiplexing scheme is different from the secondmultiplexing scheme, where M is an integer greater than 1. Themultiplexing scheme used for the CSI-RS ports of the second pattern setis configured via signaling of the base station.

For example, the first code division multiplexing scheme used for theCSI-RS ports of the first pattern sets uses a code division multiplexinglength of 2, and the code division multiplexing scheme used for theCSI-RS ports of the second pattern set uses a code division multiplexinglength of 2 or 4; or the first code division multiplexing scheme usedfor the CSI-RS ports of the first pattern set uses the code divisionmultiplexing length of 4, and the code division multiplexing scheme usedfor the CSI-RS ports of the second pattern set uses the code divisionmultiplexing length of 2 or 4, where the code division multiplexinglength used for the CSI-RS ports of the second pattern set is configuredvia signaling of the base station.

Embodiment 5

In the embodiment, the M candidate RS resource patterns are divided intothree sets, a first multiplexing scheme is used for CSI-RS ports of thefirst pattern set, a second multiplexing scheme is used for CSI-RS portsof the second pattern set, the first multiplexing scheme or the secondmultiplexing scheme is used for CSI-RS ports of the third pattern set,and the first multiplexing scheme is different from the secondmultiplexing scheme, where M is an integer greater than 1. Themultiplexing scheme used for the CSI-RS ports of the third pattern setis configured via signaling of the base station.

For example, the first code division multiplexing scheme used for theCSI-RS ports of the first pattern sets uses a code division multiplexinglength of 2, the second code division multiplexing scheme used for theCSI-RS ports of the second pattern set uses a code division multiplexinglength of 4, and the code division multiplexing scheme used for theCSI-RS ports of the third pattern set uses the code divisionmultiplexing length of 2 or 4; or the first code division multiplexingscheme used for the CSI-RS ports of the first pattern set uses the codedivision multiplexing length of 4, the second code division multiplexingscheme used for the CSI-RS ports of the second pattern set uses the codedivision multiplexing length of 2, and the code division multiplexingscheme used for the CSI-RS ports of the third pattern set uses the codedivision multiplexing length of 2 or 4, where the code divisionmultiplexing length used for the CSI-RS ports of the third pattern setis configured via signaling of the base station.

Embodiment 6

In the embodiment, when the number of the ports is larger than a secondthreshold value (TH2), at least two types of RS densities are used forthe M candidate RS resource patterns, where M is an integer greater than1.

For example, when TH2 is 8 and the number of the ports is 12, there arethe following three types of RS densities: one RE in each PRB pair foreach port, one RE in every two PRB pairs for each port and two REs inevery three PRB pairs for each port; and when TH2 is 8 and the number ofthe ports is 16, there are the following two types of RS densities: oneRE in each PRB pair for each port and one RE in every two PRB pairs foreach port.

Embodiment 7

In the embodiment, the M candidate RS resource patterns are divided intotwo sets, a first type of RS density is used for the first pattern set,a second type of RS density is used for the second pattern set, and thefirst type of RS density is different from the second type of RSdensity, where M is an integer greater than 1.

For example, the RS density used for the first pattern set is one RE ineach PRB pair for each port, and the RS density used for the secondpattern set is one RE in every two PRB pairs for each port; or, the RSdensity used for the first pattern set is one RE in every two PRB pairsfor each port, and the RS density used for the second pattern set is oneRE in each PRB pair for each port.

Embodiment 8

In the embodiment, in an RS resource pattern set, the inter-CSI-RS-portmultiplexing scheme uses a code division multiplexing length of 4, andfour REs for mapping of each group of code division multiplexed RSsymbols are located on two continuous subcarriers.

As shown in FIG. 8, in the case that the number of the ports is 16,CSI-RSs of each group are code division multiplexed to four REs ofcontinuous subcarriers, there are two RS resource patterns in FIG. 8:CSI-RS RE for config #0 and CSI-RS RE for config #1, and in each RSresource pattern, the 16 ports are divided into four groups: {15, 16,17, 18}, {19, 20, 21, 22}, {23, 24, 25, 26} and {27, 28, 29, 30}, andthe four REs for code division multiplexing mapping of the ports of eachgroup are located on two continuous subcarriers.

As shown in FIG. 9, in the case that the number of the ports is 12, eachgroup of the CSI-RSs are code division multiplexed to four REs ofcontinuous subcarriers, there are three RS resource patterns in FIG. 9,i.e., CSI-RS RE for config #0, CSI-RS RE for config #1 and CSI-RS RE forconfig #2, and in each RS resource pattern, the 12 ports are dividedinto three groups: {15, 16, 17, 18}, {19, 20, 21, 22} and {23, 24, 25,26}, and the four REs for code division multiplexing mapping of theports of each group are located on two continuous subcarriers.

Embodiment 9

In the embodiment, a maximum frequency interval of REs on a PRB pair ina pattern of which an RS density is one RE in each PRB pair for eachport is not larger than (namely, less than or equal to) the number,which is a third threshold value (TH3), of subcarriers, that is, themaximum frequency interval is a difference between a highest frequencyand a lowest frequency of frequency bands in which the REs are located.

Alternatively, the third threshold value is 9.

FIG. 10 is a pattern with a maximum frequency interval of not largerthan 9 on a PRB pair in the case that an RS density is one RE in eachPRB pair for each port. In FIG. 10, there are totally two patterns:CSI-RS RE for config #0 and CSI-RS RE for config #1, where a maximumfrequency interval on a PRB pair in the pattern 0 is 7 subcarriers, anda maximum frequency interval on a PRB pair in the pattern 1 is 9subcarriers.

Embodiment 10

In the embodiment, a maximum time-domain interval of REs on each RSresource pattern is smaller than a fourth threshold value (TH4), and themaximum time-domain interval is a difference value between a last oneand a first one of OFDM symbols in which the REs are located.

Alternatively, the fourth threshold value is 6.

FIG. 11 is a pattern with a maximum time-domain interval smaller than 6.In FIG. 11, there are totally two patterns: CSI-RS RE for config #0 andCSI-RS RE for config #1, a maximum time-domain interval of the pattern 0is 5, and a maximum time-domain interval of the pattern 1 is 4.

Alternatively, the fourth threshold value is 5.

FIG. 12 is a pattern with a maximum time-domain interval smaller than 5.In FIG. 12, there are totally two patterns: CSI-RS RE for config #0 andCSI-RS RE for config #1, a maximum time-domain interval of the pattern 0is 1, and a maximum time-domain interval of the pattern 1 is 4.

Embodiment 11

In the embodiment, when the number of the ports is 12, in an RS resourcepattern set, each RS resource pattern corresponds to an 8-port RSresource pattern, an RS density is two REs in every three PRB pairs foreach port, and different RS resource patterns correspond to different RSresource patterns under the number of the ports of 8.

FIG. 13 is a pattern with an RS density of two REs in every three PRBpairs for each port in the case of 12 ports. In FIG. 13, there aretotally five patterns: CSI-RS RE for config #0, CSI-RS RE for config #1,CSI-RS RE for config #0=2. CSI-RS RE for config #3 and CSI-RS RE forconfig #4.

Embodiment 12

In the embodiment, when the number of the ports is 12, in an RS resourcepattern set, each RS resource pattern corresponds to a 4-port RSresource pattern and a 2-port RS resource pattern and is on the same twoOFDM symbols, an RS density is one RE in every two PRB pairs for eachport, and different RS resource patterns correspond to differentcombinations of 4-port RS resource patterns and 2-port RS resourcepatterns.

FIG. 14 is a pattern with an RS density of one RE in every two PRB pairsfor each port in the case of 12 ports. In FIG. 14, there are totallyfive patterns: CSI-RS RE for config #0, CSI-RS RE for config #1, CSI-RSRE for config #0=2. CSI-RS RE for config #3 and CSI-RS RE for config #4.

Embodiment 13

In the embodiment, when the number of the ports is 12, in an RS resourcepattern set, each RS resource pattern corresponds to an 8-port RSresource pattern and two 2-port RS resource patterns, moreover, the RSresource patterns with the two numbers of ports are located on the sametwo OFDM symbols and adjacent in frequency domain, an RS density is oneRE in each PRB pair for each port, and different RS resource patternscorrespond to different combinations of 8-port RS resource patterns and2-port RS resource patterns.

FIG. 15 is a pattern formed by a combination of an 8-port pattern andtwo 2-port patterns in the case that the number of the ports of 12. InFIG. 15, the RS density of the pattern is one RE in each PRB pair foreach port.

Embodiment 14

In the embodiment, when the number of the ports is 12, in an RS resourcepattern set, each RS resource pattern corresponds to two groups ofports, a first code division multiplexing scheme is used for the firstgroup of ports, a second code division multiplexing scheme is used forthe second group of ports, and the first code division multiplexingscheme is different from the second code division multiplexing scheme.

For example, ports {15, 16, 17, 18, 19, 20, 21, 22} form the first groupand adopt the first code division multiplexing scheme, and ports {23,24, 25, 26} form the second group and adopt the second code divisionmultiplexing scheme; or, the ports {15, 16, 17, 18, 19, 20, 21, 22} formthe first group and adopt the second code division multiplexing scheme,and the ports {23, 24, 25, 26} form the second group and adopt the firstcode division multiplexing scheme.

Embodiment 15

In the embodiment, in an RS resource pattern set, each RS resourcepattern corresponds to two groups of ports, a first code divisionmultiplexing scheme is used for the first group of ports, the first codedivision multiplexing scheme or a second code division multiplexingscheme is used for the second group of ports, and the first codedivision multiplexing scheme is different from the second code divisionmultiplexing scheme. The code division multiplexing scheme used for thesecond group of ports is configured via signaling of the base station.

For example, a code division multiplexing scheme with a length of 2 isused for the first group of ports, a code division multiplexing schemewith a length of 2 or 4 is used for the second group of ports, and thecode division multiplexing scheme used for the second group of ports isconfigured via signaling of the base station; or, the code divisionmultiplexing scheme with the length of 4 is used for the first group ofports, the code division multiplexing scheme with the length of 4 isused for the second group of ports, and the code division multiplexingscheme used for the second group of ports is configured via signaling ofthe base station.

Embodiment 16

In the embodiment, in an RS resource pattern set, each RS resourcepattern corresponds to two groups of ports, a first code divisionmultiplexing scheme or a second code division multiplexing scheme isused for the first group of ports, the first code division multiplexingscheme or the second code division multiplexing scheme is used for thesecond group of ports, and the first code division multiplexing schemeis different from the second code division multiplexing scheme. The codedivision multiplexing scheme used for the first group of ports isconfigured via signaling of the base station, and the code divisionmultiplexing scheme used for the second group of ports is configured bythe signaling of the base station.

For example, a code division multiplexing scheme with a length of 2 or 4may be used for the first group of ports, the code division multiplexingscheme with the length of 2 or 4 may be used for the second group ofports, and the code division multiplexing schemes used for the firstgroup of ports and the second group of ports are configured viasignaling of the base station.

Embodiment 17

In the embodiment, in an RS resource pattern set, the inter-CSI-RS-portmultiplexing scheme uses a code division multiplexing length of 4, andeach group of code division multiplexed RS symbols are mapped to REs ona PRB pair in a 4-port resource pattern.

FIG. 4 is a pattern in the case of 4 ports. There are totally 10patterns in FIG. 4: CSI-RS RE for config #0, CSI-RS RE for config #1,CSI-RS RE for config #2, CSI-RS RE for config #3, CSI-RS RE for config#4, CSI-RS RE for config #5, CSI-RS RE for config #6. CSI-RS RE forconfig #7, CSI-RS RE for config #8 and CSI-RS RE for config #9.

FIG. 16 is mapping of each group of code division multiplexed RS symbolsonto REs of a PRB pair in a 4-port resource pattern. In FIG. 16, theports are grouped as follows: {15, 16, 19, 20}, {17, 18, 21, 22}, {23,24, 27, 28} and {25, 26, 29, 30}, and the code division multiplexed RSsymbols of each group are mapped to REs of a PRB pair in a 4-portresource pattern.

Embodiment 18

In the embodiment, in the case that the code division multiplexinglength is 4, a manner for mapping at least one group of code divisionmultiplexed RS symbols to REs is configured via signaling of the basestation. There are two types of mapping manners, the first mappingmanner is mapping the code division multiplexed RS symbols ontocontinuous subcarriers, and the second mapping manner is mapping thecode division multiplexed RS symbols onto discontinuous subcarriers.

For example, the first mapping manner is mapping the code divisionmultiplexed RS symbols onto two continuous subcarriers, and the secondmapping manner is mapping the code division multiplexed RS symbols ontotwo subcarriers having a frequency-domain difference value of 6subcarriers.

Embodiment 19

In the embodiment, the M candidate RS resource patterns are divided intotwo sets. In a first pattern set, code division multiplexed RS symbolsin a same group are mapped to REs in a first mapping manner; and in asecond pattern set, a second mapping manner is used to map code divisionmultiplexed RS symbols in a same group to REs, and the first mappingmanner is different from the second mapping manner, wherein M is aninteger greater than 1.

For example, a continuous subcarrier mapping type manner is used for thefirst pattern set, and a discontinuous subcarrier mapping type manner isused for the second pattern set.

Embodiment 20

In the embodiment, in the case that the code division multiplexinglength is 4 and the ports are grouped for code division multiplexing, atype of a port grouping manner is configured via signaling of the basestation, and there are two types of port grouping manners.

For example, the first port grouping manner is as follows: {15, 16, 17,18}, {19, 20, 21, 22}, {23, 24, 25, 26} and {27, 28, 29, 30}; and thesecond port grouping manner is as follows: {15, 16, 19, 20}, {17, 18,21, 22}, {23, 24, 27, 28} and {25, 26, 29, 30}.

Embodiment 21

In the embodiment, the M candidate RS resource patterns are divided intotwo sets, a first port grouping manner is used for CSI-RS ports of thefirst pattern set, a second port grouping manner is used for CSI-RSports of the second pattern set, and the first port grouping manner isdifferent from the second port grouping manner, where M is an integergreater than 1.

For example, the first port grouping manner is used for the CSI-RS portsof the first pattern set, and the second port grouping manner is usedfor the CSI-RS ports of the second pattern set.

The first port grouping manner is as follows: {15, 16, 17, 18}. {19, 20,21, 22}, {23, 24, 25, 26} and {27, 28, 29, 30}; and

the second port grouping manner is as follows: {15, 16, 19, 20}, {17,18, 21, 22}, {23, 24, 27, 28} and {25, 26, 29, 30}.

A basic principle and main characteristics of the disclosure andadvantages of the disclosure are displayed and described above. Thedisclosure is not limited to the embodiments, the principle of thedisclosure is illustrated in the embodiments and the specification,various variations and improvements may further be made to thedisclosure without departing from the spirit and scope of thedisclosure, and these variations and improvements shall fall within thescope of the disclosure applying for protection.

An embodiment of the disclosure further provides a storage medium.Alternatively, in the embodiment, the storage medium may be configuredto store program codes configured to execute the following operations.

In S1, configuration information of a CSI-RS is determined.

In S2, signaling including the configuration information of the CSI-RSis generated.

In S3, the signaling including the configuration information of theCSI-RS is transmitted.

Here, the configuration information may include: a number of ports, RSresource pattern information and an inter-CSI-RS-port multiplexingscheme; and when the number of the ports is larger than 1, there are Mcandidate RS resource patterns for the CSI-RS, where M is an integergreater than 1.

Alternatively, in the embodiment, the storage medium may include, butnot limited to: various media capable of storing program codes, such asa U disk, a Read-Only Memory (ROM), a Random Access Memory (RAM), amobile hard disk, a magnetic disk or an optical disk.

Alternatively, specific examples in the embodiment may refer to examplesdescribed in the abovementioned embodiments and optional implementationmodes and will not be elaborated in the embodiment.

Obviously, those skilled in the art should know that each module or eachstep of the disclosure may be implemented by a universal computingdevice, and the modules or steps may be concentrated on a singlecomputing device or distributed on a network formed by a plurality ofcomputing devices, and may alternatively be implemented by program codesexecutable by the computing devices, so that the modules or steps may bestored in a storage device for execution with the computing devices, theshown or described steps may be executed in sequences different fromthose described here in some circumstances, or may form each integratedcircuit module respectively, or multiple modules or steps therein mayform a single integrated circuit module for implementation. As aconsequence, the disclosure is not limited to any specific hardware andsoftware combination.

The above is merely the preferred embodiment of the disclosure and notintended to limit the scope of protection of the disclosure. For thoseskilled in the art, the disclosure may have various modifications andvariations. Any modifications, equivalent replacements, improvements andthe like made within the spirit and principle of the disclosure shallfall within the scope of protection of the disclosure.

INDUSTRIAL APPLICABILITY

By the embodiments of the disclosure, under the condition of providing alarger RS multiplexing factor, an overhead is reduced, channelestimation quality is improved, transmission and receiving complexity islowered, and meanwhile, 12 or 16-port CSI-RS transmission can besupported.

The invention claimed is:
 1. A method for configuring a Channel StateInformation-Reference Signal (CSI-RS), comprising: determining, by abase station, configuration information of the CSI-RS; generating, bythe base station, signaling comprising the configuration information ofthe CSI-RS; and transmitting, by the base station, the signalingcomprising the configuration information of the CSI-RS, wherein theconfiguration information comprises: a number of CSI-RS ports, RSresource pattern information and an inter-CSI-RS-port multiplexingscheme, and the RS resource pattern information and theinter-CSI-RS-port multiplexing scheme are jointly-coded in the signalingcomprising the configuration information of the CSI-RS; wherein when thenumber of the CSI-RS ports is larger than 1, the CSI-RS has M candidateRS resource patterns, where M is an integer greater than 1; wherein theM candidate RS resource patterns are divided into a first pattern setand a second pattern set, each of the first pattern set and the secondpattern set comprises one or more candidate RS resource patterns, afirst multiplexing scheme is used for CSI-RS ports in each candidate RSresource pattern of the first pattern set, a second multiplexing schemeis used for CSI-RS ports in each candidate RS resource pattern of thesecond pattern set, and the first multiplexing scheme is different fromthe second multiplexing scheme; and wherein the first multiplexingscheme is a first code division multiplexing with an orthogonal codelength of 2, the second multiplexing scheme is a second code divisionmultiplexing with an orthogonal code length of
 4. 2. The methodaccording to claim 1, wherein when the number of the CSI-RS ports islarger than a first threshold value, at least two inter-CSI-RS-portmultiplexing schemes are used for the M candidate RS resource patterns.3. The method according to claim 1, wherein when the number of theCSI-RS ports is larger than a second threshold value, at least two typesof RS densities are used for the M candidate RS resource patterns. 4.The method according to claim 1, wherein the M candidate RS resourcepatterns are divided into two sets, a first type of RS density is usedfor a first set, a second type of RS density is used for a second set,and the first type of RS density is different from the second type of RSdensity.
 5. The method according to claim 1, wherein in an RS resourcepattern set, the inter-CSI-RS-port multiplexing scheme uses a codedivision multiplexing length of 4, and four Resource Elements (REs), towhich each group of code division multiplexed RS symbols are mapped, arelocated on two continuous subcarriers.
 6. The method according to claim1, wherein the M candidate RS resource patterns are divided into twosets; in a first set, code division multiplexed RS symbols in a samegroup are mapped to REs in a first mapping manner; in a second set, codedivision multiplexed RS symbols in a same group are mapped to REs in asecond mapping manner, and the first mapping manner is different fromthe second mapping manner.
 7. The method according to claim 1, whereinthe M candidate RS resource patterns are divided into two sets, a firstport grouping manner is used for CSI-RS ports of a first set, a secondport grouping manner is used for CSI-RS ports of the second set, and thefirst port grouping manner is different from the second port groupingmanner.
 8. An apparatus for configuring a Channel StateInformation-Reference Signal (CSI-RS), comprising: a processor; and amemory storing codes, which, when executed by the processor, cause theprocessor to perform a method for configuring the CSI-RS, the methodcomprising: determining configuration information of the CSI-RS;generating signaling comprising the configuration information of theCSI-RS; and transmitting the signaling comprising the configurationinformation of the CSI-RS, wherein the configuration informationcomprises: a number of CSI-RS ports, RS resource pattern information andan inter-CSI-RS-port multiplexing scheme, and the RS resource patterninformation and the inter-CSI-RS-port multiplexing scheme arejointly-coded in the signaling comprising the configuration informationof the CSI-RS; wherein when the number of the CSI-RS ports is largerthan 1, the CSI-RS has M candidate RS resource patterns, where M is aninteger greater than 1; wherein the M candidate RS resource patterns aredivided into a first pattern set and a second pattern set, each of thefirst pattern set and the second pattern set comprises one or morecandidate RS resource patterns, a first multiplexing scheme is used forCSI-RS ports in each candidate RS resource pattern of the first patternset, a second multiplexing scheme is used for CSI-RS ports in eachcandidate RS resource pattern of the second pattern set, and the firstmultiplexing scheme is different from the second multiplexing scheme;and wherein the first multiplexing scheme is a first code divisionmultiplexing with an orthogonal code length of 2, the secondmultiplexing scheme is a second code division multiplexing with anorthogonal code length of
 4. 9. The apparatus according to claim 8,wherein when the number of the CSI-RS ports is larger than a firstthreshold value, at least two inter-CSI-RS-port multiplexing schemes areused for the M candidate RS resource patterns.
 10. The apparatusaccording to claim 8, wherein the M candidate RS resource patternscomprise that: when the number of the CSI-RS ports is larger than asecond threshold value, at least two types of RS densities are used forthe M candidate RS resource patterns.
 11. The apparatus according toclaim 8, wherein in an RS resource pattern set, the inter-CSI-RS-portmultiplexing scheme uses a code division multiplexing length of 4, andfour Resource Elements (REs), to which each group of code divisionmultiplexed RS symbols are mapped, are located on two continuoussubcarriers.
 12. The apparatus according to claim 8, wherein the Mcandidate RS resource patterns are divided into two sets, in a firstset, code division multiplexed RS symbols in a same group are mapped toREs in a first mapping manner; in a second set, code divisionmultiplexed RS symbols in a same group are mapped to REs in a secondmapping manner, and the first mapping manner is different from thesecond mapping manner.
 13. The apparatus according to claim 8, whereinthe M candidate RS resource patterns are divided into two sets, a firstport grouping manner is used for CSI-RS ports of a first set, a secondport grouping manner is used for CSI-RS ports of a second set, and thefirst port grouping manner is different from the second port groupingmanner.